US Secretary of State John Kerry has issued a warning to Syria, saying "the threat of force is real" if it does not destroy its chemical weapons.

Speaking at a joint news conference with Israeli Prime Minister Benjamin Netanyahu in Jerusalem, he said the focus must now be on ending the violence and humanitarian crisis in Syria.

But he again warned that US military strikes were a possibility if President Bashar al Assad does not comply with a newly-brokered US and Russian deal to strip him of his chemical stockpiles.

"The threat of force remains, the threat is real," he said. "We cannot have hollow words in the conduct of international affairs."

Under the deal, Syria has seven days to give the UN details on the amount and locations of its chemical arsenal.

Mr Netanyahu said diplomacy could only work if it was coupled with the threat of force, and Syria needed to be stripped of its chemical weapons to "make our entire region a lot safer".

Syrian troops and rebels continue to clash on the streets of Damascus

"The world needs to ensure that radical regimes don't have weapons of mass destruction because as we have learned in Syria, if rogue regimes have weapons of mass destruction they will use them," he said.

"The determination the international community shows regarding Syria will have a direct impact on the Syrian regime's patron Iran. Iran must understand the consequences of its continued defiance of the international community by its pursuit toward nuclear weapons."

Video:US Says 'Threat Of Force Is Real'

The Syrian government has welcomed the agreement on its chemical weapons disarmament as "a victory" for Damascus.

"On one hand, it helps the Syrians emerge from the crisis and on the other it has allowed for averting war against Syria," Syrian minister of state for national reconciliation Ali Haidar said in an interview with Russian news agency Ria Novosti. "It's a victory for Syria that was achieved thanks to our Russian friends."

Mr Haidar gave Syria's first reaction to the disarmament plan as warplanes and artillery bombarded rebel-held areas of Damascus. He said the deal would prepare the ground for peace talks between President Assad's forces and the rebels.

Video:Putin 'Running Rings Around Obama'

But opposition leaders have called the international focus on poison gas a sideshow, and dismissed talk the plan might herald peace talks. They said Mr Assad had stepped up an offensive with ordinary weaponry now the threat of US air strikes had receded.

Mr Kerry is due to hold talks on the Syria crisis with British Foreign Secretary William Hague, French President Francois Hollande and French Foreign Minister Laurent Fabius on Monday.

During the meeting, France is expected to push for its demand that Mr Assad be hauled before the International Criminal Court and tried for war crimes in a conflict that has killed more than 110,000 people since March 2011.

"I’m less concerned about style points. I’m much more concerned with getting the policy right," said Mr Obama.

Milam said: "There is no mistaking the irritation felt in the Oval Office about Vladimir Putin. Whatever they say about working together, we can probably read more into Obama’s dig that 'he doesn’t share our values'."

In reference to next weekend's UN deadline, when Mr Assad is due to deliver details of his deadly arsenal, Milam added: "The feeling is that Washington must have been secured some guarantee from Moscow, or even Damascus, that the Assad regime will not miss that deadline.

"If not, having escaped from the corner he'd painted himself into with his red line, he will be right back there this time next week."